The immune system is an incredibly important aspect in maintaining good health. It is a very costly bodily mechanism to run and as a result can be easily weakened. In no particular order, the following is a list of things you can and should do to keep your immune system fully functional.

Eat Your Fruits and Veggies

Fruits and vegetables are unique in that they come from plants. The nutrients they provide are also unique as some cannot be found in any other food. Of particular importance to immune function are Vitamins A, C, and E. These vitamins function as antioxidants, neutralizing harmful free radicals which can hinder immune cell function.

Look For Lean Proteins

Lean protein sources, like that found in fish and poultry, contains many essential amino acids. Amino acids are used throughout the body, but are particularly important for the production of specialized immune cells.

Focus on Good Fats

While we certainly need some fat to survive, certain fats in large amounts can hinder the immune system. The notoriously harmful trans fats found in many fried foods and commercial baked goods contribute to chronic low-grade inflammation. The immune system can become distracted by this inflammation, allowing many harmful microorganisms to slip past the body’s defenses. Instead, eat limited amounts of saturated fats like those in olive oil, nuts, and avocados.

Try Some Tea

Green tea is rich in an antioxidant type called catechin. Canadian researchers have demonstrated the ability of a catechin to limit viral replication. Catechins are also thought to improve immune cell function as well as prevent inflammation.

Prevent with Probiotics

Helpful bacteria which line the digestive tract prevent the colonization of harmful microorganisms by competing for space and nutrients. Researchers have also noticed immune-stimulating activity from these same helpful bugs. A recent study involving 33 women who ate plain yogurt for 2 weeks showed a 30% increase in T-cell (a type of immune cell) count. To get the probiotic benefits of yogurt, look for brands that contain “live and active cultures”.

Avoid Excessive Alcohol

In addition to being a nervous system depressant, alcohol can also cause the depression of the immune system. A type of white blood cell called the neutrophil is responsible for migrating to the site of infection where they engulf and destroy harmful microorganisms. Alcohol impairs the neutrophil’s ability to find its way. Alcohol is also an antimicrobial and can kill protective bacteria lining the gut if consumed in excess.

Engage in Exercise

Those who are overweight or obese generally have high levels of triglycerides and cholesterol in their blood. These compounds can interfere with an immune cell’s ability to recognize foreign microorganisms. Exercise can lower cholesterol and triglycerides as well as provide a method of stress relief, also important to immune function.

Stabilize Stress

Chronic stress causes high blood pressure, increased heart-rate, and many other conditions which when experienced constantly can upset immune function. (Think of how many people get sick around high-stress holidays like Christmas). Doing things that make you laugh (watching a sitcom) or feel deeply relaxed (meditation) are incredibly important for relieving stress.

Get Plenty of Sleep Regularly

The immune benefits of good sleep are likely related to the stress caused by sleep deprivation. Most people need at least 7 hours of sleep each night – not just on the weekends – to get the rejuvenating effects of sleep that keep stress at a minimum.

Think Optimistically

It’s amazing how much our health is related to our mood. Optimism can counteract the negative effects on our immune system caused by stress and anxiety. Try to stay cool and collected, and always look for the silver lining, in situations that could otherwise be upsetting.

Sources:
http://pubs.niaaa.nih.gov/publications/arh26-4/257-263.htm
http://www.thevegetariansite.com/health_stress.htm
http://www.cnn.com/2007/HEALTH/diet.fitness/11/14/cl.best.defense/index.html